In pixiv this tag is currently relevant to a total of 20,082 illustrations that are submitted to pixiv as of February 14, 2014.
This tag is mainly used for original creation and manga/anime/novel titles. This tag may also refer to male characters that resemble the same or similar cuteness of female characters.
While the tag こんな可愛い子が女の子のはずがない is also used, The submission for "男の娘" however far exceeds the former in terms of submission number.
Boys and Girls
High School Girl
Do list any related illustrations for "Trap"/"男の娘".